my crank keeps coming loose

:angry: my left crank keeps coming loose for no reason , and nothing is broken , what do i do , help :astonished:

More details would help us help you. What brand of uni is it? What have you done to try to keep it tight up till now? Are they cotterless cranks or splined? What kind of riding do you do? How long does it take for the crank to loosen?

ive bourght some loctite threadlock witch should work as it works for bikes . if you have any better advice then its a : qu-ax with cotterless cranks i think and i use it at a local club indoors so nothing to extreme and it takes about a week or so depending how much i ride :thinking:

did you take the crank off and look at the hole in the crank and the square part i goes onto on the hub, if it is rounded then your crank could be wobbling and loosening the bolt slowly. The same thing happened to my first unicycle and i ended up destroying the hub and crank

I guess the first thing to check would be to make sure that the pedals are on the correct side. There should be a L (for left) and R (for right) on the backside of the cranks.
Do the pedals come loose as well, or just the cranks?

One thing you could try it to pound it on good with a rubber mallet or with a hammer using a chunk of wood protecting your crank then tighten up the bolt with some blue locktight on it.

If your crank is coming loose the interface where it connects to the hub is probably deformed. Pounding it on might re-deform it in the shape of the axle.

If that does not work either your crank, axle or both are wrecked beyond repair.

just the cranks :thinking:

my friend had the same probleme… :stuck_out_tongue:
He just cleaned his cranks(inside, were the hub is…) and now it is a lot better!! :wink:

ill try that aswell :sunglasses:

I have the same problem

I have been experiencing this exact same problem lately. I have a 24" torker lx. I have tightened the cranks as tight as I could numerous times and usually by the time I get down the street they are loose again. I have tried cleaning the crank and securing it with locktight. It doesn’t look like the crank is deformed either but I’m not too sure. The locktight kept it secure for a couple of days but came loose after a small jump (maybe a couple of inches, but nothin it couldn’t have handled before). Maybe I am just riding a little too hard for it, but that does not seem likely. Any ideas would be nice!

The crank arm bolts need to be fairly tight. If you used a short wrench, they could be too loose, even if it felt like you were really cranking them down.

If you rode it too far when the problem first started, it is possible that the crank arms are rounded from side to side. Then they will come loose even if you tighten them, because they will be able to rock side to side. If this is what happened, you may be able to use them a little longer by putting a thin washer between the crank and the crank bolt. It worked on my sister’s 20in Schwinn, but if you have the wrong washer, it won’t add any pressure, so it won’t make a difference. If you do this, you’ll definitely need a drop of blue Locktite or Permatex on the bolt. You risk damaging the hub though… Since the hub is usually more durable than the crank, it may be time to replace the cranks before the hub is damaged.

But… I had a similar problem on my mountain bike years ago. I thought the crank bolt was tight, but when I bought a torque wrench and looked up the torque specs, I found that it was supposed to be much tighter.

thanks but your a tad late, look at the date on threads next time :wink: